3.4" Ammonite (Promicroceras) Cluster - Marston Magna, England

Ammonite (Promicroceras) Cluster - Marston Magna, England #216613

This is a 3.4" tall stone containing many small ammonite fossils. The ammonites are of the species Promicroceras marstonense and are Lower Jurassic (~200 million years old) in age. This rock is quarried near Marston Magna, Somerset, England. Locally this ammonite filled rock is known as "Marston Marble".

The piece has been painstakingly prepared with mechanical tools to expose all of the individual ammonite fossils on one side. The base of the specimen is cut flat to stand unassisted.

Ammonites were predatory cephalopod mollusks that resembled squids with spiral shells. They are more closely related to living octopuses, though their shells resemble that of nautilus species. True ammonites appeared in the fossil record about 240 million years ago during the Triassic Period. The last lineages disappeared 65 million years ago at the end of the Cretaceous.

What an ammonite would have looked like while alive.